The present invention relates to generally a television receiver capable of receiving both the American and European system television channels and more particularly a radio frequency section thereof.
At present various television systems are used which are different in sound intermediate frequency, television channels, the field frequency and so on. For instance, television systems used in U.S.A. and European countries such as Germany are different as shown in TABLE 1 below.
TABLE 1 ______________________________________ U.S.A. European ______________________________________ Low-band VHF range 54-88 MHz 47-68 MHz High-band VHF range 174-216 MHz 174-230 MHz UHF range 470-890 MHz 470-862 MHz Sound intermediate frequency 4.5 MHz 5.5 MHz Field frequency 60 Hz 50 Hz ______________________________________
In order to receive such various television channels, a television set adapted for a particular television system must be provided. Alternatively, a television receiver must be provided with a switching means for tuning in a particular television system. Especially in the case of the small-sized, battery-operated portable television sets which must be operated with any television system in the world, they must be provided with such switching means as described above.